Method of making hexamethylenetetramine



Patented Sept; 2,1930

GUSTAVE E. L A DT ANDWILLIAM e lmmsm, 6F NoRRIsToWN,@EPENNSYLVANIA,

3 ,essmlvons, my MESNE nssrenmnurs, V

1 VPARY, or. NEWARK; DELAWARE, A? conronArro-lv or DELAWARE mo. CONTINENTAL DIAMOND METHOD or Making,.HEXAMETRYLENE' ;ET AMrNE I 01 1i inventionrelatesto a method of mak' Water which is presentin commercial alcohol ,anid the amount {of Water 'formedchem'ically "duringthe process is sul'lic'ient to keep the hex; V

amethylenetetrami-ne to some extent in solu mg hexamethylenetetramiiie and has" for one object thepreparation of this substance in an organic solvent, I Y

;A further object of our'inventijongis to proy. 7 tion.

vide a more economical method forpreparing' hexamethylenetetramine thanhas heretofore beenused, which method eliminates-two steps in-the'p'lant-practice noW employed. I "1 0 1 Another object of our invention it'o pro vide a method of preparing hexamethylenetet -l ramine Which is continuous, "that is to'say,

from- Which the hexamethylenetetramine may besepaifated in crystalline form While thereae't -en involving the preparation of the subs s tance continues in the'solution, I p =Afurther object of ourinvention is to pronvide" a, process; for the manufacture of synthetfio resinvarnish vehicles by which "hex-i amethylenetetraminewill be prepared in the organic solution in Which the initial condenl sation productof the synthetic resin isdis-- 1 solved-or is to bedissolved, thereby obviating sultingfalso in vsolvents. I i v- At the present time, v he'xamethylenetetra g mine is prepared commercially by passing a--' the 1 necessity of separating the 'h'eXamethyl enetetra'mine .inia crystalline form, v and rev; a materlalj savln'g in organic SlZIQHLIlIOf ammonia gas or a solutionofamimonium hydroxide into a Water solutionof" formaldehyde whereupon the ammonia and; the formaldehyde react, liberatingjwater and forming the hexamethylenetetramine." Hex-g amethylenetramine relatively soluble: in ater and therefore must be recovered by] I levaporationi In order-that the hexamethyl- I enetet-ramin'e may be-in" ajpurified; crystallinetionofthe formaldehyde and-the ammonia in "form, *it is redissolved crystallized therefrom; y o p V Our invention is characterized by the reac- 1 in alcohol and l re an organic solvent solution, thereby elimii'iat in'g two steps'now used in plant practice, namely,*the evaporation of the Water from the originalrea'ction products andlthe subsequent rte-crystallization of the hexamethyl- I V 'enetetramine fromthelalcohol. We preferably employ as the organic solvent ordinary,

* commercial alcoliol;wliich,'as is Well known,

1 be represented as: follows;

. stances.

'1 np plic'aueh "filed Januar 4, 1927. amma; 159,914

contains 5%of W'ateri; ,Thissmall" amount of The formaldehyde may be'di ssolv'edin theflalcohol; and thefgajseousammjonia passed j therein o1'-.[tlie processinely; be reversed by 5 dissolving "the 'ammon1'a'-"1n the alcohol and passing formaldehyde into itJA satisfactory out then a continuous process for the manutinned until the solution becomessaturated and the hexamethyl'enetetraminecrystallizes 1 facture .of hexamethylenetetramine fresults 'i In; the-"preparation off'heiiametliylenetetra: if mine from; formaldehyde and ammonia; six

inol sjof th e former reactwitli"4niols of. the,

"from which 'the.crystalline liexametliylene tetram'inemay'be removed from the reaction I lat r to "form, the compound. "Tlfiefreactionj 4N-H3=i o ,Formalde; Ammonia Heix'amethylene .7 hyde V tetr'amine V Hence the preparation of the compound according tothefmethod here disclosed; the d ratio-ofithetworeaoting lcomponents iffthey V A aretofl passed simultaneously into j,th'e g5 1 However; one-'"of'ithe; components-is "disk if Sol/Veil i 1 -h o n s tha the ot e i lp dj I "into thelsolution until thereaction"iscom I V a i plete, Where-upon more-ofthe-component solution maybej added and the proc'ess'fcon h tinned; The"balancingof the iauoiorn eg 1 iv solution are" kept:fa'pproX-imately inth is ratio.

components is; Within the skill of onefamiliarfor example; at times Yin] order gto; insur'e a presentan excess of one'fof use reactin 7 Sin o gan c i' bl the temp eratui f the sci-mien is below the boi llng 'with chemicalpreparationsand'l willtoisoine' 2' Y 7' e tentdependonthe condition 'ofope rat'iom' crnnpletereaction itinayjbe aclvisable tojhave i 't l v. V

temperature of 75 C. for the solution isthe maximum at. which the reaction should be carried out. This temperature is just below the boiling-point of alcohol.

The synthetic resin industry in the manufacture of synthetic resin yarnishes uses large quantities of alcohol. in the preparation of these solutions; To this synthetic resin solution" in alcohol often times crystalline hexamethylenetetramine is added, in order .that a potentially reactive varnish will be formed by'which term is meant OIlQ'tllilt can be converted by heat easily and quickly'i'nto a hard, infusible synthetic resin. By the use of the solution of hexamethylenetetramine herein described, the potentially reactive varnish can be preparedjsimply by adding the initial condensationproduct thereto without any recoveryof the hexamethylenetetramine --Witl1 its.accompanying'loss ofalcohol. This directstep therefore of great vvalue in this industry for the manufacturers of synthetic resin varnishes may saturate I the alcohol which istobe used as a solution in the manufacture of. the varnish with the herramethylenetet-ramine and there will be no subsequent losses either of the material or of the alcohol. Attention is called to our co-pending application SerialNo. 216,787, filed August 31, 1927,

as a division of the present case. Inthis divisionalcase, claims are directed to this specific process. I

An optional method of preparing a synthetic resin varnish which has proved to be satisfactory comprises passing-the gaseous reacting components, that is the formaldehyde andammonia, into, a solution of the synthetic resin in alcohol. In this case, the

formaldehyde and/ammonia will react to form hexamethylenetetraminein the varnish itself thereby rendering it potentially reactive. Attention is' called to our co-pending application Serial No. 216,788, filed August 31, 1927, as a division of the present case. In this divisional case,clztims are directed to thisfspecific process lVhile the above processes are applicable for many types of synthetic resins, they are especially adapted for use with that type of synthetic resin known as phenolicfcondcnsation products, that'is to say one in whicha phenol is reacted with another compound such asformaldehyde,glycer1ne,furfural and i the like.v

* Considerable"'modification in the proportions used and in the methods of carrying out the processare possible with no departure from the essential features of ourinvention.

ave claim: I v

1. A processfor the manufacture ofhexamethylenetetramine .which comprises reacting jammonia and formaldehyde in' alcohol at a temperaturebelow 7 5. C. i

. 2. A'process forthe manufactureof hexaformaldehyde and ammonia into alcohol at a temperature below 75 C.

3. A process for the manufacture of heXa- I methylenetetramine which comprises passing formaldehydeand ammonia into alcohol at a .temperature below 75 C. with the subsequentremoval of the crystals as the solution becomes saturated.

4. A continuous process for the manufacture of hexamethylenetetramine which comprises-reacting ammonia and formaldehyde in alcoholic solution at a temperature below 75 C. and removing the crystals of hexamethylenetetramine as they separate from the solution.

5. A process for preparinga synthetic resin varnish vehicle which comprises pass ing formaldehyde and ammonia into alcohol at a ten'iperature below 75 Cl to form hexamethylenetetramine, there being present sufficient alcohol to keep the hexamethylenetetramine' in. solution.

6. A process for the manufacture of heXa methylenetetramine which-comprises passing 

